Gun blast suppressor



Feb. 10, 1959 sc s 2,872,848

GUN BLAST SUPPRESSOR Filed D90. 1, 1954 Fig. 1

In In L i N N o INVENTOR.

KARL E. SCHUESSLER BY g United t tes Patent- 2,872,848 GUN BLAST SUPPRESSOR Karl E. Schuessler, Philadelphia, Pa., assignor to the UnitedStates of America as represented by the Secretary of the Navy Theinvention described herein may be manufactured and used by or for theGovernment of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

' The present invention relates to a gun blast suppressor for machineguns and more particularly to a gun blast suppressor arranged to preventdamage to structural members immediately adjacent to the muzzle of amachine gun due to the blast effect of the gases released therefrom at ahigh velocity and under extremely high pressure when the gun is fired.

Various types of gun blast suppressors have been constructed. However,all known types are relatively large and heavy and they fail to reducethe gun blast sufiiciently to preclude serious damage to structuralparts immediately adjacent to the muzzle of a gun. These deficienciesbecome particularly significant for two reasons in aircraftinstallations wherein the guns must be fully enclosed within structuralcomponents of the airframe such as the wings; first, because in allaircraft installations size and weight of each part are criticalfactors; and, second, every structural component of the airframe of anaircraft is necessarily designed with a very small safety factor due tothese same space and weight limitations, with the resuit that nosubstantial damage to such members can be tolerated since it woulddangerously weaken the structure. Consequently, gun blast suppressorshave henceforth been used only infrequently for gun installations onaircraft, notwithstanding the need in this type of installation for theprotection which an effective gun blast suppressor would afford.

The present invention contemplates an improved gun blast suppressorassembly reduced in size and weight and capable of a greater reductionin blast pressure. Hence, the device described in the presentapplication is particularly suitable for gun installations in aircraft.

An object of the present invention is to provide a gun blast suppressorof substantially increased efliciency."

Another object is the provision of a light weight, compact gun blastsuppressorassembly for machine guns.

A final object of this invention is to provide a gun blast suppressorassembly capable of minimizing gun blast damage to structural membersdisposed immediately adjacent to the muzzle of a gun.

The exact nature of this invention as well as other objects andadvantages thereof will be readily apparent from consideration of thefollowing specification in relation to the annexed drawing wherein:

Fig. 1 shows a cross section taken upon the longitudinal axis of apreferred embodiment of the present invention,

Fig. 2 shows a cross section taken on line 22 of Fig. l, and

Fig. 3 shows a cross section taken on line 3-3 of Fig. 1.

Referring now to thedrawing, wherein like reference characters designatelike or corresponding parts, the showing in Fig. 1 includes an assemblysupporting member Patented Feb. 10, 1959 11 generally cylindrical inshape and flared outwardly at one end to form a hollow tapered portion13 which in turn forms the outer surface of a tapered annular passage 15and provides the mechanical connection with the outer tube 21 of the gunblast suppressor assembly. The supporting member 11 also includes meansfor con meeting the gun blast suppressor assembly to the muzzle of amachine gun which means may conveniently comprise an internally threadedportion for engagement with existing threads on the barrel of the gunand a slotted clamping means 19 adjacent thereto, shown best in Fig. 2.The outer tube 21 is an elongated hollow cylindrical member forming theouter surface of the gun blast suppressor assembly and permanentlyconnected at one end to the portion 13 of the supporting member 11 byany suitable means, such as a welded joint. The outer tube 21 in turnsupports a relatively smaller elongated hollow cylindrical membercomprising the inner tube of the annular gun blast suppressor assemblyand disposed concentrically within the outer tube 21. The inner andouter tubes are interconnected at the end of the outer tube most remotefrom its connection to the portion 13 of the supporting member 11 bymeans of an annular end plate 25 which may be sealably engaged with therespective tubes by any suitable means such as welded joints asillustrated inFig. 1 or threaded engagement of the end plate with theends of the respective tubes. The respective tubes 21 and 23 along withthe end plate 25 form an elongated annular chamber 31 fully enclosed andsealed except for the annular opening adjacent the portion 13 of thesupporting member 11. In order to provide the most favorableconfiguration for the chamber 31, the inner face of the end plate 25 isprovided with an annular depression which is substantially semi-circularin cross section to facilitate the reversal of flow of gases whichstrike the end plate. The inner tube 23 also requires support adjacentits opposite end to accurately maintain it in proper align.- ment withthe outer tube 21. This additional support may comprise a plurality ofradially extending braces 37, one of which is shown in Fig. 1, allfixedly secured to the inner tube 23 as by welding or formed integrallytherewith. The outer ends of the braces 37 should be in bear: ingengagement with the inner surface of the outer tube 21, but preferablyare not attached thereto, because the tubes may shift relative to eachother as they become heated in use. The end of the inner tube 23' remotefrom the end plate 25 is fitted with a tapered annular deflector member33 fixedly securedthereto by suitable means such as welding, and sodisposed that it forms the inner surface of the tapered annular passage15. In addition, the member 33 is provided with a circumferentialshoulder portion 35 around its outer periphery and adjacent its point ofattachment to the inner tube 23, to restrict reverse flow through thepassage 15. It will be noted that the braces 37 are preferably spacedsufficiently from the deflector 33 and its shoulder 35 that they do notadversely interfere with the flow of gases through the passage 15.

In operation, the device comprising the present invention is fixedlyattached to the muzzle end of a machine gun with the inner tube 23 inaxial alignment with the bore of the gun barrel. As each projectile istired from the gun, it passes out of the muzzle and through inner tube23 and thence out of the end of the inner tube 23 remote from the muzzleof the gun. As the projectile passes through the central opening in thetapered annular deflector member 33 which is just slightly larger thanthe outer circumference of the projectile and is concentric with the gunbarrel, the tapered outer surface of the deflector member which at itswidest point is about one and one-half times the diameter of the innertube 23 is effective to initially separate the gases behind theprojectile from the projectile as it leaves the muzzle of the gun anddivert these gases through the passage 15. As the gases emerge from themuzzle of the gun they continue to expand and, due to the pressure inthe muzzle, are forced through the passage 15 and into the annularchamber 31 defined by the inner surface of the outer tube 21, the outersurface of the inner tube 23, and the end plate 25 wherein the gases cancontinue to expand until they reach the end plate 25. Here they strikethe radially curved surface of the end plate 25, bounce back in theopposite direction toward the muzzle of the gun, and pass over theturbulence creating shoulder 35 of the deflector 33 before returningthrough the passage 15, and thence out through the inner tube 23. Duringthis process in which the gases are turned twice through 180 degrees andsubjected to a turbulent flow their velocity is greatly reduced andmeanwhile the projectile has traveled the length of the inner tube 23.Then, the gases pass out through the inner tube at greatly reducedpressure and velocity,'in comparison to the conditions under which theyinitially leave the muzzle of the gun, so that the discharge of gasesfrom a gun equipped with the device comprising the instant invention isextended over a relatively longer time interval.

Thus, the present invention provides a compact, light weight means foreffectively reducing the pressure and velocity of the gases releasedfrom the muzzle of a machine gun when it is fired and arranged tominimize impingement of these gases upon structural members adjacent tothe muzzle of the gun, thereby substantially reducing the possibility ofserious damage to such structures.

In an alternate configuration designed to provide a more concentratedweight distribution for a gun assembly fitted with the presentinvention, structure defining the annular passage 15 may be located atthe right end of the device as illustrated in Fig. 1 and the respectivetubes 21 and 23 may be sufficiently enlarged to permit the barrel of agun to extend well within the elongated annular gun blast suppressorassembly to a point immediately adjacent the relocated annular passage.With such an arrangement, the gun blast suppressor assembly is disposedmuch closer to the center of gravity of the gun assembly upon which itis mounted. In addition, two or more units of the type shown in Fig. 1can be mounted in tandem, if desired, to produce a cumulative eflectupon the gases discharged from a gun.

Obviously, many modifications and variations of the present inventionare possible in the light of the above teachings. It is, therefore, tobe understood that Within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. A gun blast suppressor assembly, comprising a first elongatedcylindrical hollow imperforate tubular member, a second relativelylarger elongated cylindrical hollow imperforate tubular member disposedconcentrically of and in spaced relation to said first member, agenerally conical hollow supporting element connected at its larger endto one end of said second member and attached at its other end to themuzzle of a gun barrel to fixedly support said second member in axialalignment with the barrel and projecting forwardly from the muzzle endthereof, an imperforateannular end plate sealably and fixedlyinterconnecting said first and said second tubular members at the end ofsaid second tubular member remote from the conical supporting element,said annular end plate having a radially curved annular depression uponits inner face, and a tapered annular deflector element attached at itslarger end to the end of said first member nearest the supportingelement, said deflector element being spaced from and disposedconcentric of said supporting element to define an annular venturi typepassage therebetween adjacent the muzzle of a gun.

2. A gun blast suppressor assembly comprising an elongated hollowannular housing encompassing an elongated axial opening therethrough of:sufficient size to permit the passage of a projectile, said housingincluding an elongated outer tubular imperforate member, a generallycylindrical supporting member securely attached to the muzzle end of amachine gun and provided with a flared portion fixedly secured to oneend of said outer tubular member to fixedly maintain said outer tubularmember in alignment with the barrel of a gun and projecting forwardlyfrom the muzzle end thereof, an imperforate annular end plate connectedto the other end of said outer tubular member and supporting one end ofa relatively smaller elongated inner tubular imperforate member ofsubstantially the same length as the outer tubular member, said endplate being eifective to seal the annular space between said members toform a substantially closed chamber Within said housing for thetemporary entrapment of the gases released when a projectile leaves themuzzle of a gun, and an annular flared deflector member fixedly securedto the opposite end of said inner tubular member and provided at itsouter periphery with a shoulder projecting beyond the outercircumference of said inner tubular member, said deflector member beingdisposed in spaced relation to the flared portion of said supportingmember to form a single restricted annular passage sloping outwardlyfrom a point adjacent to the muzzle of a gun to which said suppressorassembly is attached to the annular space between said outer and innertubular members.

3. A device as described in claim 2, in which said end plate is providedwith a radially semi-circular annular depression covering its entireinner surface.

References {lited in the file of this patent UNITED STATES PATENTS1,017,003 Kenny Feb. 13, 1912 1,860,276 Luce et al May 24, 19322,101,849 Green Dec. 14, 1937 2,112,660 Hudson Mar. 29, 1938 2,503,491Janz Apr. 11, 1950 2,796,005 Shapel June 18, 1957 FOREIGN PATENTS 30,240Great Britain 1909 30,960 France Oct. 30, 1919 101,841 Switzerland Jan.16, 1925 562,475 Germany Oct. 26, 1932 338,113 Great Britain Nov. 10,1930

